Automotive 3.6V to 36V, 3.2A Buck Converter with Wide Vin 280mA LDO Regulator

TPS65321-Q1 is not recommended for new designs
Although this product continues to be in production to support previous designs, we don't recommend it for new designs. Consider one of these alternates:
open-in-new Compare alternates
Drop-in replacement with upgraded functionality to the compared device
TPS65321A-Q1 ACTIVE Automotive 3.6V to 36V, 3.2A Buck Converter with Wide Vin 280mA LDO Regulator The TPS65321A-Q1 is a replacement for the TPS65321-Q1.

Product details

Configurability Hardware configurable Vin (min) (V) 3.6 Vin (max) (V) 36 Vout (min) (V) 1.1 Vout (max) (V) 20 Iout (max) (A) 3.2 Features Eco-mode, Enable, Overcurrent protection, Power good, Thermal shutdown, UVLO fixed Iq (typ) (mA) 0.035 Rating Automotive Switching frequency (max) (kHz) 2500 Operating temperature range (°C) -40 to 125 Processor supplier Generic Processor name Generic Shutdown current (ISD) (typ) (µA) 2 Product type Microcontrollers
Configurability Hardware configurable Vin (min) (V) 3.6 Vin (max) (V) 36 Vout (min) (V) 1.1 Vout (max) (V) 20 Iout (max) (A) 3.2 Features Eco-mode, Enable, Overcurrent protection, Power good, Thermal shutdown, UVLO fixed Iq (typ) (mA) 0.035 Rating Automotive Switching frequency (max) (kHz) 2500 Operating temperature range (°C) -40 to 125 Processor supplier Generic Processor name Generic Shutdown current (ISD) (typ) (µA) 2 Product type Microcontrollers
HTSSOP (PWP) 14 32 mm² 5 x 6.4
  • Qualified for Automotive Applications
  • AEC-Q100 Qualified with the Following Results:
    • Device Temperature Grade 1: –40°C to +125°C Ambient Operating Temperature
    • Device HBM ESD Classification Level 2
    • Device CDM ESD Classification Level C4B
  • One High-VIN Step-Down DC-DC Converter
    • Input Range of 3.6 V to 36 V
    • 250-mΩ High-Side MOSFET
    • Maximum Load Current 3.2 A, Output Adjustable 1.1 V to 20 V
    • Adjustable Switching Frequency 100 kHz to 2.5 MHz
    • Synchronizes to External Clock
    • High Efficiency at Light Loads With Pulse-Skipping Eco-mode™ Control Scheme
    • Maximum 140-µA Operating Quiescent Current
    • Reset Output-Pin (Active Low, Open-Drain)
  • One High-VIN Low-Dropout (LDO) Voltage Regulator
    • Input Range of 3 V to 36 V
    • 280-mA Current Capability With Typical 35-µA Quiescent Current in No-Load Condition
    • Low-Dropout Voltage of 300 mV at
      IO = 200 mA (Typical)
  • Overcurrent Protection for Both Regulators
  • Overtemperature Protection
  • 14-Pin HTSSOP Package With PowerPAD™ Integrated Circuit Package
  • Qualified for Automotive Applications
  • AEC-Q100 Qualified with the Following Results:
    • Device Temperature Grade 1: –40°C to +125°C Ambient Operating Temperature
    • Device HBM ESD Classification Level 2
    • Device CDM ESD Classification Level C4B
  • One High-VIN Step-Down DC-DC Converter
    • Input Range of 3.6 V to 36 V
    • 250-mΩ High-Side MOSFET
    • Maximum Load Current 3.2 A, Output Adjustable 1.1 V to 20 V
    • Adjustable Switching Frequency 100 kHz to 2.5 MHz
    • Synchronizes to External Clock
    • High Efficiency at Light Loads With Pulse-Skipping Eco-mode™ Control Scheme
    • Maximum 140-µA Operating Quiescent Current
    • Reset Output-Pin (Active Low, Open-Drain)
  • One High-VIN Low-Dropout (LDO) Voltage Regulator
    • Input Range of 3 V to 36 V
    • 280-mA Current Capability With Typical 35-µA Quiescent Current in No-Load Condition
    • Low-Dropout Voltage of 300 mV at
      IO = 200 mA (Typical)
  • Overcurrent Protection for Both Regulators
  • Overtemperature Protection
  • 14-Pin HTSSOP Package With PowerPAD™ Integrated Circuit Package

The TPS65321-Q1 device is a combination of a high-VIN DC-DC step-down converter, referred to as the buck regulator, with an adjustable switch-mode frequency from 100-kHz to 2.5-MHz, and a high-VIN 280-mA low-dropout (LDO) regulator. The input range is 3.6 V to 36 V for the buck regulator, and 3 V to
36 V for the LDO regulator. The buck regulator has an integrated high-side MOSFET with an active-low, open-drain power-good output-pin (nRST). The LDO regulator features a low-input supply current of 45-µA typical in no-load, also has an integrated MOSFET. Low-voltage tracking feature enables TPS65321-Q1 to track the input supply during cold-crank conditions.

The buck regulator provides a flexible design to fit system needs. The external loop compensation circuit allows for optimization of the converter response for the appropriate operating conditions. A low-ripple pulse-skip mode reduces the no-load input-supply current to maximum 140 µA.

The device has built-in protection features such as soft start, current-limit, thermal sensing and shutdown due to excessive power dissipation. Furthermore, the device has an internal undervoltage-lockout (UVLO) function that turns off the device when the supply voltage is too low.

The TPS65321-Q1 device is a combination of a high-VIN DC-DC step-down converter, referred to as the buck regulator, with an adjustable switch-mode frequency from 100-kHz to 2.5-MHz, and a high-VIN 280-mA low-dropout (LDO) regulator. The input range is 3.6 V to 36 V for the buck regulator, and 3 V to
36 V for the LDO regulator. The buck regulator has an integrated high-side MOSFET with an active-low, open-drain power-good output-pin (nRST). The LDO regulator features a low-input supply current of 45-µA typical in no-load, also has an integrated MOSFET. Low-voltage tracking feature enables TPS65321-Q1 to track the input supply during cold-crank conditions.

The buck regulator provides a flexible design to fit system needs. The external loop compensation circuit allows for optimization of the converter response for the appropriate operating conditions. A low-ripple pulse-skip mode reduces the no-load input-supply current to maximum 140 µA.

The device has built-in protection features such as soft start, current-limit, thermal sensing and shutdown due to excessive power dissipation. Furthermore, the device has an internal undervoltage-lockout (UVLO) function that turns off the device when the supply voltage is too low.

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Technical documentation

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* Data sheet TPS65321-Q1 36-V Step-Down Converter With Eco-mode™ and LDO Regulator datasheet (Rev. B) PDF | HTML 22 Jun 2017
Application note Low Quiescent Current With Asynchronous Buck-Converters at High Temperatures 20 Jul 2016
Technical article How a Wide VIN integrated buck and LDO can power your automotive system – part 2 PDF | HTML 30 Jun 2016
Application note Interfacing TPS57xxx-Q1 and TPS65320-Q1 Family Devices With Low Impendence Exter 08 Dec 2015
Application note TPS65321-Q1 Design Checklist 23 Nov 2015
EVM User's guide TPS65321EVM (HVL125A) User's Guide (Rev. A) 02 Nov 2015

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Evaluation board

TPS65321EVM — TPS65321-Q1 36V Step-Down Converter with EcoMode™ and LDO Regulator Evaluation Module

The Texas Instruments TPS65321EVM evaluation module (EVM) helps designers evaluate the operation and performance of the TPS65321 Switch Mode Power Supply – Multiple-output voltage regulator.

User guide: PDF
Not available on TI.com
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HTSSOP (PWP) 14 View options

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